Biotic transformation reactions anaerobic

Alterations may include transformation, degradation, and changes in speciation or ionization. Transformation occurs when a contaminant is chemically altered by the addition of oxygen, hydrogen, or nitrogen, or is combined with or bound to another chemical. Abiotic transformations may include chemical oxidations or reductions in aerobic or anaerobic environments, respectively. Biotic transformations may be carried out by bacteria and fungi in the environment, or may take place within the bodies of plants and animals. Transformations may either make the chemical more or less toxic, depending on the reaction involved. If the chemical is broken down... 

The operation of these hydrolytic reactions is independent of the oxygen concentration of the system so that—in contrast to biotic degradation and transformation—these reactions may occur effectively under both aerobic and anaerobic conditions. 

Environmental Fate. Further investigation would resolve the discrepancies in the data for anaerobic degradation of 1,1,2-trichloroethane. Additional studies are needed to characterize the nature of the transformation and to clarify whether biotic, abiotic, or catalyzed abiotic reactions are involved. Will these reactions generally occur under environmental conditions A determination of the half-life in representative groundwater and sediment-water systems would be useful. From the available evidence, biodegradation in aerobic systems appears unlikely, although additional studies, particulary in soil, are desireable and would clarify this point. 

---